HARRISBURG — Pennsylvania's top public health official is leaving Gov. Ed Rendell's administration for an executive post at Temple University Health System in Philadelphia.

Dr. Calvin Johnson, the state Health Department secretary since April 2003, is resigning effective Sept. 26, Rendell spokesman Chuck Ardo said.

He has been appointed vice president and chief medical officer of Temple's health system, which includes four hospitals and a network of community-based physician practices, effective Oct. 15, the health system said in a separate announcement.

"I wasn't necessarily seeking it, but the opportunity presented itself," said Johnson, who grew up in Philadelphia and still has family there. "The more I looked at it, it seemed like it was a good opportunity to continue the kind of work I've been doing here (in state government), but in a more focused way."

Johnson earns $136,120 annually as health secretary. He declined to say how much he will be paid in his new job.

During his tenure, Johnson has been responsible for overseeing a wide variety of public health programs.

Rendell credited Johnson with helping implement several health care reform measures, including steps to reduce infections contracted by patients in hospitals.

Johnson also was a leading advocate for a statewide ban on smoking.